Recent developments in the design and powering of semiconductor based lighting devices, particularly those known as LEDs and OLEDs (Organic Light Emitting Diodes), have provided a significant increase in light production efficiency, measured say, in lumens per watt. Compact power conversion units have also been developed which are efficient in their conversion of household AC voltage levels to a lower DC level suitable for powering LED and other similar semiconductor devices. Additionally, there exist semiconductor light emitting devices that are usable using AC voltage sources.
However, the lighting devices currently available using the advanced technologies referred to above generally do not provide the same shape or form factor associated with the standard incandescent light bulb (lamp). Philips Manufacturing Co. does make an LED based lamp that attempts to duplicate the form factor of a standard light bulb but they do not employ light guide like structures.
It is also noted that various governmental institutions at numerous levels have opted to replace the standard incandescent lamp with more energy efficient devices. The incandescent lamp has, however, completely permeated the design and structure of myriads of associated structures ranging from desk and floor lamps, lamp fixtures, refrigerators, luminaires, drop lights, etc. Accordingly, it is desirable to provide an efficient light source that duplicates as closely as possible the shape and size of the conventional incandescent lamp in as many situations as possible.
Attempts have been made to address some of the issues presented above, but they have not fully solved all of the concomitant problems. For example, in U.S. Pat. No. 7,344,290 issued on Mar. 19, 2008, the inventors Huang et al. appear to describe an LED based lamp structure resembling a tubular fluorescent lamp device. Like other efforts described below, this patent relies on the use of light guides and reflectors. For the purposes of the present application, and as is well understood in the art, a light guide is an optical device intended for the transmission of light from a source point to a destination point with losses along its length designed to be minimal. The art also considers light guides and light pipes to be essentially the same devices.
In U.S. Pat. No. 7,228,052 issued to Wei-Cheng Lin on Jun. 5, 2007, one or more LEDs are employed in conjunction with a light pipe, but the resulting configuration bears no resemblance to a standard light bulb. In U.S. Pat. No. 7,111,972 issued on Sep. 26, 2006, Coushaine et al. describe a lamp using LEDs and a light pipe which conducts light directly from an LED light source to a deflector. Again, the resulting devices shown therein bear little similarity to the congenital incandescent light bulb.
In published patent application U.S. 2010/0283369 A1 published on Nov. 11, 2010, Chen describes an LED bulb and lamp holder. However, again, it is a structure which uses light guides to direct light from a source directly to a destination. The structure of the devices described in this publication which are described as light guides rather appear merely to be conically shaped cavities having reflective properties for directing light from one or more LEDs directly to the outside of the device. Again, while there is an attempt therein to duplicate the shape of a standard incandescent bulb, the resulting structure actually has more of a flat ellipsoid shape.
In published patent application US 2010/0208488 A1 published Aug. 19, 2010, Luo appears to describe an LED lamp structure which is similar to that described by Coushaine et al. above in that light is directed through a light guide directly to a deflector structure.
As can be seen from the above, the art has failed to leverage the benefits provided by LED and other semiconductor light emitting devices in a manner that facilitates the construction of lighting devices having the same form factor of the ubiquitous incandescent lamp.
From the above, it is therefore seen that there exists a need in the art to overcome the deficiencies and limitations described herein and above.